Apparatus for cleaning the screen in a well



Nov. 30, E937. M, M. KINLEY.

APPARATUS FOR CLEANING THE SCREEN IN A WELL Filed Feb. 2o, w55 2 sheets-sheet 1 ou 0J of e 2225@ w www ,4 .,jw 7 M. u. wa mm ....m fL/ l/kfwfle I f :y/t um ,f f E0 O WV/. Ill VM. .T f .Wn-M 1l H .m wH/.W m I I W M 7 /Jw 7 i1/T21 /Z r .B v l 0 n@ a., 2, P.. fxswgyyxxw 5 W o w n n, a wwmf 5u 6 7 o z. n o o o o :v i. JWH- Fr d n l I 10 0 u v nv So 87 0? im M M wwf/n? nwmu n@ La/ma n 4 M 4 5 fo V. /y l URWJWWWVUVUPQDAREF.,MQLEUJNMM w avi-a0 NOV. 30, 1937. M. M. KlNLEY APPARATUS FOR CLEANING THE SCREEN IN A WELL 2 Sheets-Sheet 2 KKR .my miv/.nua a Filedk Feb. 20, 1955 a www@ INVENTOR /Vg/m/r /Va atented Non. 3Q, i937 TES it, .f

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1N .a WELL G1 'EEE SCREEN ll/iyron Macy ey, Tulsa, Okla. Application February Ztl, 1935, SerialNo. 7,368

13 Claims.

This invention relates to a method of and apparatus for cleaning the screen in a well of accumulations tending to block flow of fluid therethrough. For example, in certain oil wells, the fluid producing formation is so soft and crumbly that the oil exuding therefrom carries with it large quantities of the material. Since this material is very abrasive in character and destructive to the pumping apparatus, various types of screens are employed to exclude its entry into the pumping system. The excludedmaterial, therefore, accumulates on the outer side of the screens and blocks -iiow of the uid. When this occurs, it has heretofore been found more practicable to replace the screen with a new one, which results in a very expensive operation.

It is, therefore, one of the principal objects of the present invention to provide means whereby such screens may be cleaned in place at a minimum of trouble and expense with the result that the eiciency of the screen is restored to approximately its original flow capacity.

In accomplishing this and other objects of the invention, hereinafter pointed out, I have provided improved details of structure, the preferred form of which is illustrated in the accompanying drawings, wherein: I

Fig. 1 is a vertical section of the bottom of a well in which is lowered a screen cleaning apparatus embodying the -features of the present invention.

Fig. 2 is an enlarged vertical section through the well and cleaning apparatus.

Fig. 3 is an enlarged section illustrating the step of ignitingf the explosive charge.

Fig. 4 is a similar view illustrating movement of the piston under the propelling force of the explosion to force uid reversely through the apertures of the screen.

Fig. 5 is a detail vertical section through the ring portion of the. apparatus, particularly illustrating the method of sealing the breech thereof.

Fig. 6 is a horizontal section on the line 6 6,

Fig. 2.

` Fig. 7 is a section on the line 1 1, Fig. 2, particularly illustrating the nozzle from which (Cl. 16a-2o) sleeved thereover and having a plurality of open' ings 8 of suicient size to exclude the intermixed material from the oil entering the casing through the. perforations 6.

When the well is initially brought in there may be sufficient formation pressure to cause natural ow of oil through the casing; however, in most oil sands, the formation' pressure gradually recedes until it is not sufficient to cause flow from the well and some form of mechanical pumping apparatus must be used and it is for the purpose of protecting the pumping apparatus that the screen 'I has been inserted over the well casing. Otherwise, the crumbling material would be destructive to the working parts of the pumping apparatus. After such a well has been in operation, the excluded material builds up around the screen I to block the free entry of oil into the casing, resulting in a greatly diminished flow.

As above pointed out, it is the object of the present invention to provide for cleaning the screen of accumulated material in such a manner that it is not necessary to remove the casing or screen from the well. This is accomplished by creating a reverse flow of uid through the apertures of the screen under the propelling force of an explosive charge, as now to be described.

9 designates a cleaning apparatus constructed in accordance with the present invention and which includes a. cylindrical body I0 of suitable diameter to be freely lowered within the casing l. In the illustrated instance the body is made up of a cylinder section II, a nozzle I2, a guide section I3, and a firing head I 4.

The cylinder section II is constructed of relatively heavy material and has an inner bore extending axially thereof to .provide a piston and firing chamber I5 of a length to retain suicient fluid I6 for flushing the screen as later described. The lower end of the cylinder is externally threaded as at I1 to engage the internal threads I8 formed in the upper end of the nozzle I2.

The nozzle I2 includes a cylindrical body of larger diameter than the `section II so that the periphery I 9 thereof extends in relatively close relation with the inner wall of the casing 4 and is provided with an axial bore 20 forming a continuationvof the piston chamber I5. Formed in the wall 2| thereof isA a plurality of-radial slots 22 from which the fluid I6 is ejected through the screen as later described. The bore 20 extends below the lower ends of the slots and is slightly enlarged in diameter to provide a check chamber 23 for checking and stopping movement of the piston 24 when it reaches the bottom end of the nozzle. 'I'he lowerl end of the nozzle is preferably rounded as at 25 and is provided with an internally threaded socket 26 for threadedly connecting the upper end of a rod 21 which is adapted to support the apparatus in cleaning position within the well.

The upper end of the section II is internally threaded as at 28 to receive the external threads 29 of the ring head by which the guide section I3 is attached to the section I I, and which houses a portion of the firing mechanism.

The firing head member I4 includes a central portion 3| of substantially the same diameter as the exterior diameter of theV cylinder and oppo. sitely extending connecting portions 32 and 33 conforming in diameter to the chamber I5 and the inner diameter of the guide section I3 respectively. The portion 32 carries the threads 29 and forms with the central portion 3I an annular shoulder 34 tightly engaging the upper end 35 of the section II to seal the upper end of the chamber I5. against leakage. The portion 33 is externally threaded as at 36 to engage the internal threads 31 on the lower end of the guidev section I3 and also forms an annular'shoulder 38 to seat the lower end of the guide section as clearly shown in Fig. 3. I

The guide section I3 includes a. pipe 36 having an outer diameter corresponding to the outer 'diameter of the section II andthe upper end thereof has a closed top 40 provided with an axialv opening 4I for passing a suspension cable 42 by which the apparatus is lowered into the well! The opposite sides of the guide section have slotted. openings 43 to provide free movement of the well fluid therethrough upon actuay tion of a weight 44 later described.

Extending axially throughthe ringhead I4 is a borev45 of substantially smaller diameter than the chamber I 5 to slidably mount a firing i pin 46 and house a primer 41 which is retained by a plug 46 that is threaded into the lower end ofthe boreas a't 49 and has a protruding portion 5Il`projecting within a powderchamber .52 formed within the piston 24, the plug 48 being provided with an axial fire emitting opening 5I through which fire from the primer 'is directed into rthe powder chamber.

'Ihe upper end of the piston 24. has an inwardly and downwardlyI tapered annular rim 53 for engaging against a correspondingly tapered y seat 54 that is provided on the lower face of the connecting portion 32 of the firing head I4 so that when the piston is in Yits uppermost position and engaging the seat 54, the inclined surfaces willhelp to maintain a gas tight seal between the piston and the coupling member.

The ring mechanism includes the firing pin 46 which comprises a cylindrical bar freely slidable within thebore and has aflattened upper end 55 and a cone-shaped lower. end 56 to engage respectively against a sealing disk 51 and a fulminating cap 58 von'the primer 41. The Vsealing disk 51 is preferably `formed of Soft metal commodating a plunger 64. The plunger 64 includes a shank 65 that is slidable in the bore 62 and a head 66 movable within the socket 63 t0 puncture the sealing disk 51 upon actuation of the weight.

The upper end of the firing pin projects from the guide and is normally protected against accidental operation of the weight by a bushing 61 that is threaded in a socket 68 formed in the upper end of the guide and which is provided with a head portion 69 by which it is rotated about the ring pin t0 move it into the threaded socket for exposing the end of the ring pin to the action ofthe weight 44.

' In order to seal the breech portion of the firing mechanism after piercing of the sealing disk, the head of the firing pin includes a cone-shaped collar 10 spaced from Athe end thereof and having a flattened annular face 1I to seat against the bottom 12 of the socket 63 under pressure of gas generated in the powder chamber, as later described. The weight 44 includes a heavy body of metal of cylindrical shape to slide freely within the guide section and which has a neck on its upper end in which the end of the cable is babbited or otherwise attached as illustrated at 13, Fig. 2.

In using an apparatus constructed as described for cleaning a well screen, the pumping apparatus is firstl removed from the well. 'Ihe cleaning apparatus is then assembled and prepared forl firing by inserting the firing pin 46 within the bore of the firing head I4. The primer 41 is then inserted within the lower end of the bore and retained by the plug 48. The sealing disk 51 is then inserted in the threaded socket 59 0f the coupler to seat against the shoulder 60.

The plunger 64 is then sleeved within its guide 6I so that the head thereof is retained within the recess 63 and the guide is threaded into the firing head in sealing contact with the disk 51. The bushing 61 is then threaded into the socket of the guide to protect/the upper end of the plunger against accidentaldischarge of the primer.

The section II is threaded on the firing head I4 after Ywhich the chamber 52 is filled with an explosive and the piston inserted in the lower end ofthe cylinder to seat against the tapered seat 54 of the ring head I4; To retain the piston in this position a plurality of sealing disks 14 are theninserted through the bottom end of .the cylinder and moved into engagement with the lower face of 'the piston after which the peripheries thereof are caulked against the wall of therlng chamber to provide a liquid tight seal and prevent entrance of liquid past the piston into the powder chamber.

With the parts assembled as described, it is obvious that the powder chamber is sealed from y below by the disks 14 and from above by the disk 51. The nozzle I2 is then threaded on the lower end of the section II, after which the guide secthen threaded .into the lower end of the nozzle which is of suflicient length to support the nozzle at the upper end of the screen when the lower end of the rod engages the bottom of the Well. The bushing '57 is then adjusted to expose the projecting end of the plunger.

The apparatus is then lowered within the casing until it is stopped by the rod 2i engaging with the bottom of the well. Upon entering the well fluid, the nozzle and piston chamber are filled with well fluid which is admitted thereto through the slots 22. During lowering of the apparatus into the well, the weight d@ is retained in the upper end of the guide section, but when the rod 2l engages the bottom of the well, downward movement of the apparatus is stopped to free the weight dd so that a quick release on the tension of the cable results in striking of the weight against the plunger ed driving the end-thereof through the sealing disk l and the ring pin against the fulminating cap oi the primer, igniting the primer and causing fire to be directed through the bore of the plug it into the powder chamber of the piston to ignite the powder and generate sufficient gas to drive the piston 2Q with great 'force toward the check chamber 23 in the lower end of the nozzle.

Movement of the piston 2d forces the duid in the piston chamber i thereahead and squirts it out through the slots 22 of the nozzle and through the apertures of the screen to break up the material clinging to the outer surface thereof and which is blocking the apertures therein.

After the upper end of the piston has moved past the upper portion of the slots Q2, the gas which has been generated is tree to escape through the slots of the nozzle to supplement the action of the fluid in cleaning the screen.

In the meantime the plunger tti is forced back so `that the collar thereon engages the seat l2 thereby preventing escape of the combustion pressure through the breech of the apparatus.

When the lower end of the piston enters the check chamber 23, fluid is trapped therein to check any destructive force of the piston so that it does not injure ythe apparatus and the apparatus can be again used by reloading the piston and inserting a new primer as previously described.' Attention is directed to the arrangement of the nozzle ports so that when the piston has come to rest the piston has passed the upper portion of the ports, whereby the fluid rushes back into the tubular body on the opposite side of the piston causing a reverse flow through the screen.

After firing, the apparatus is removed from the well, reloaded, and a shorter rcdi applied to the end of the nozzle. The apparatus is then relowered into the well and lired in the manner as above described to clean the portion of the screen below that cleaned in the previous operation.

The firing operations are continued until the nozzle has reached the lower end of the screen, whereupon the entire length of the screen has been cleaned of the clogging material and the,

oil is again free to flow through all the apertures in the casing.

Attention is directed to the fact that suddenness of the shot, or rather the sudden force of the fluid at 4high velocity, through the slots of the nozzle is an important factor in obtaining eiicient results.

From the foregoing, it is obvious that I have provided an apparatus which permits cleaning of the screen directly within a well so that it is not necessary to remove the screen as hasbeen the customary practice.

What I claim and desire to secure by Letters Patent is:

1. An apparatus for cleaning the inlets in a Well tubing of accumulations tending to block iiow of huid including means for lowering an explosive charge through the tubing into proximity of the inlets, means for exploding said charge, means for confining a body of fluid, a piston movable in said coniining means under force of the explosion to discharge said fluid, means for directing streams of the iiuid under movement of the piston in opposition to the natural flow of 'fluid through the. inlets, and means ior checking movement of the piston after discharge of the uid.

2. .'An apparatus for removing the material clogging the inlet opening of a well tubing including a body member having a firing chamber, a nozzle connected with the body member, means in the body member for supporting an explosive charge, a piston in the firing chamber movable in the direction of the nozzle responsive to explosion of said charge, and means for 4firing the explosive charge to efect operation of the piston.

3. An apparatus lfor removing the material clogging the inlet opening of a well tubing including a body member having a iring chamber, a nozzle connected with the body member, a piston reciprocable in the firing chamber in the direction of said nozzle and having a pocket for containing an explosive charge, and means for exploding the charge for actuating the piston.

4. An apparatus (for removing the material clogging the inlet opening of a well tubing including a body member having a iiring liquid containing chamber, a nozzle connected with the body member, means in the body member for supporting an explosive charge, a piston in the ring chamber movable in the direction of the nozzle responsive to explosion of said charge to force liquid from said chamber through the nozzle, and means for firing the explosive charge to effect operation of the piston.

51. An apparatus of the character described including a bodyv member having a firing chamber, a nozzle connected with the body member, a piston reciprocable in the firing chamber in the direction of said nozzle and having a pocket for containing an explosive charge, a firing head connected with said member, a primer in the dring head, a ring pin mounted in the head for discharging the primer to explode said charge, and means slidably carried by the body member for actuating the firing pin.

6. An apparatus of the character described including a body member having a firing chamber, a nozzle connected with the body member, a

piston reciprocable in the firing chamber in thef direction of said nozzle and having a pocket for containing an explosive charge, a firing head connected with said member and having seating contact with the piston, a primer in the firing head, a firing pin mountedin 'the head for discharging the primer to explode said charge, and means slidably carried by the body member for actuating the firing pin.

'7. An apparatus of the character described including a body member having a nring chamber, a nozzle connected with the body member, a piston reciprocable in the firingchamber in the direction of said nozzle and having a pocket for containing an explosive charge, a firing head connected with said member having a bore communicating with said pocket, a primer in said bore, a firing pin mounted in the bore for discharging the primer to explode said charge, sealing means for closing said bore ot thering head, a plunger acting against saidfsealing means to effect actuation of the firing ypin,.an,d lmeans for operating said plunger. l

8. An apparatus of the character described including a body member having a iiring chamber, a nozzle connected with the body member, a piston reciprocable in the iiring chamber in the direction of said nozzle andhaving a pocket for containing an explosive charge, a ring head connected with said member and having a bore communicating with said pocket, a primer in the iring head, a firing pin mounted in the bore of the head for discharging the primer to explode said charge, puncturable sealing means for closing said bore of the ring head, puncturing means acting against said `sealing means, means for reciprocating the puncturing means to eil'ect actuation of the'ring pin through said sealing means, and means on the ring pin responsive to explosion of said charge for reestablishing seal of the bore.

9. An apparatus of the character described including a body member having a tiring chamber, a nozzle connected with the body member, a piston reciprocable in the ring chamber in the direction of said nozzle and having a pocket for containing an explosive charge and having a tapered seat encircling said pocket, a ring head connected with said member and having a bore communicating with said pocket and having a seat for said piston to seal the pocket, a primer in the ring head, a firing pin mounted in the head for discharging the primer to explode said charge, sealing means closing said bore of the firing head', and meansfor actuating the ring pin including means for puncturing the sealing means.

10.An apparatus of the character described including a body member having a ring chamber, a nozzle connected with the body member,

a piston reciprocable in the firing chamber in the direction of said nozzle and having a pocket for containing an explosive charge, a ring head connected with said member and having a bore, a primer in said bore, a plug in the bore to retain the primer and having a tiring port opengingthe inlet openings of a well tubing including a tubular body member for containing a liquid, a nozzle connected to the tubular body member and having lateral ports arranged for discharging the liquid laterally through the inlet openings of the tubing, a piston slidable in the tubular body member, and means for reciprocating the piston to hydraulically discharge the liquid through said ports and through the inlet openings of the tubing, said piston being movable past a portion of said ports whereby fluid rushes into the tubular body on the opposite side of said piston.

12. An apparatus for removing material clogging the inlet openings of a well tubing including a tubular body member for containing a liquid, a nozzle connected to the tubular body member and having lateral ports arranged for discharging the liquid laterally through the inlet openings of the tubing, a piston slidable in the tubular body member, and means in the tubular body member for effecting an explosive charge against the piston to propel the piston in the direction of the nozzle for hydraulically discharging the -liquid through said ports.

13. An apparatus for removing material clogging the inlet openings of a. well tubing including a tubular body member for containing a liquid, a nozzle connected to the tubular body member and having lateral ports arranged for discharging the liquid laterally through the inlet openings of the tubing, a piston slidable in the tubular body member, means in the tubular body member for eiecting an explosive charge 'against the piston to propel the piston in the direction of the nozzle tor hydraulically discharging the liquid through said ports, and means in the nozzle for checking the piston.

MYaoN MACY YKINLEY. 

